1. Field
This invention relates to a battery assembly for electronic timepieces, especially for wrist watches, which has an engaging surface to determine the position thereof to the watch.
2. Prior Art
In a conventional wrist watch, as illustrated in FIG. 1, an electric battery 1 is positioned in a recess 8 formed in a substrate 2 of the watch in such manner that a negative terminal 1a of the battery faces the bottom of the recess. A springy contact member 3 fitted to the substrate 2 contacts with the periphery of a positive terminal 1b of the battery 1 and presses it against the surface of an insulating plate 6, thereby ensuring the battery to be kept in position. A springy contact member 4 has a portion extending along the bottom surface of the recess and contacting the negative terminal 1a and another portion which is sandwiched between a printed circuit board 7 and the plate 6 to produce an electric connection between a negative terminal of the board and the negative terminal 1a. In order to electrically insulate the negative terminal 1a and the member 4 from the substrate 2, there is provided an insulating sheet 5. When the battery is kept in position, the flat surface of the negative terminal contacts with the insulating sheet to determine the position in the axial direction of the battery. A timepiece dial 9 is fitted to the substrate 2.
As noted from the conventional construction of FIG. 1, since the axial position of the battery 1 is determined by receiving the negative terminal 1a at the bottom of the recess 8, it is necessary that the substrate 2 should have a portion for acting as a stop at the bottom of the recess with a sufficient thickness to resist the force imparted directly or through the contact member 4 from the battery. If the mechanical strength at that portion of the substrate is low, then the substrate and dial plate would be deformed.